Primer compositions for optical films

ABSTRACT

Articles and laminates include a substrate with a first polyester surface and a second polyester surface, a crosslinked polyurethane-based primer coated on at least the first polyester surface, and an optically clear heat activated adhesive adjacent to the crosslinked polyurethane-based primer. The articles and laminates are prepared by applying a polyurethane-based dispersion and a crosslinker on at least one polyester surface, drying the applied coating, heating while stretching the substrate and the coating to form a crosslinked primer layer on the stretched polyester surface, and applying an optically clear heat activated adhesive onto the crosslinked primer layer.

FIELD OF THE DISCLOSURE

This disclosure relates generally to optical films and laminates,specifically to primer compositions suitable for improving adhesion tooptical films.

BACKGROUND

A problem often encountered in the polymer film art relates to thedifficulty of providing strong adhesion between substrates andfunctional coatings applied to them. This is particularly true forpolyester-based substrates. To deal with the problem, a primer layer orcoating is often applied to the polyester substrate to improve adhesionbetween the substrate and the functional coating.

Among the primer technologies that have been used to provide improvedadhesion between polyester-based substrates and functional coatingsapplied to them are: the use of aminosilane coatings to improve theadhesion at subfreezing temperatures as described in U.S. Pat. No.5,064,722 (Swofford et al.); PET (polyethylene terephthalate) filmsprimed with polyallylamine coatings to improve adhesion to the PET filmof a polyvinyl butyral or ionoplast resin layer, as described in U.S.Pat. No. 7,189,457 (Anderson); glass laminates for reduction of soundtransmission that may include 3-layer laminates of polyester filmpositioned between two dissimilar polymer layers, as described in U.S.Pat. No. 7,297,407 (Anderson); and the primer layers for multi-layeroptical films where the primer layer may include a sulfopolyester and acrosslinker, as described in PCT Publication No. WO 2009/123921.

SUMMARY

Disclosed herein are articles, including articles that are optical filmsand laminates. In some embodiments, the article comprises a substratewith a first polyester surface and a second polyester surface, acrosslinked polyurethane-based primer coated on the first polyestersurface, and an optically clear heat activated adhesive adjacent to thecrosslinked polyurethane-based primer. The crosslinkedpolyurethane-based primer, in some embodiments, comprises the reactionproduct of a polyurethane-based dispersion and a crosslinker.

In some embodiments, the articles comprise a substrate with a firstpolyester surface and a second polyester surface, a crosslinkedpolyurethane-based primer coated on the first and second polyestersurfaces, and a pressure sensitive adhesive layer adjacent to thecrosslinked polyurethane-based primer on the first polyester surface.

Also disclosed are laminate constructions comprising a first glazingsubstrate comprising a first major surface and a second major surface, afilm article adhered to the first major surface of the first glazingsubstrate, the film article comprising a substrate with a firstpolyester surface and a second polyester surface, a first crosslinkedpolyurethane-based primer coated on the first polyester surface, and asecond crosslinked polyurethane-based primer coated on the secondpolyester surface, and a first optically clear heat activated adhesiveadjacent to the first crosslinked polyurethane-based primer and a layeradjacent to the second crosslinked polyurethane-based primer.

Methods of preparing an articles are also disclosed, the methodscomprise providing a substrate with a first polyester surface and asecond polyester surface, applying a curable primer composition onto atleast one of the first polyester surface or the second polyester surfaceof the substrate, wherein the curable primer composition comprises apolyurethane-based dispersion and a crosslinker, drying the curableprimer composition, heating while stretching the substrate and thecurable primer composition to form a crosslinked primer layer on thestretched polyester surface, and applying an optically clear heatactivated adhesive onto the crosslinked primer layer to form anoptically clear heat activated adhesive layer.

DETAILED DESCRIPTION

The use of films for optical applications is increasing. A wide varietyof optical films contain polyester surfaces. Optical films that containpolyester surfaces include polyester films, multi-layer films withexterior polyester film layers and films with a polyester coating orlayer on the exterior surface or surfaces. It is desirable in manyinstances to surface treat the polyester surface of the films to aid inthe ability of functional coating layers, such as adhesive layers, toadhere to the polyester surface of the films. This surface treatment caninclude physical surface treatment methods such as corona treatment,flame treatment and the like, or it can involve chemical treatment suchas, for example, the application of a primer coating. Because the filmsare often used in optical applications, it is desirable that the surfacetreatment does not substantially alter the optical properties of thefilm. Not all of the above described techniques have been successfullyused with polyester surfaces, so there still remains a need for newsurface treatments for the polyester surfaces of films, such as opticalfilms.

Heat activated adhesives are used extensively with optical films. Someclasses of heat activated adhesives are particularly difficult to adhereto polyester surfaces. This is particularly true for heat activatedadhesives such as polyvinylbutyral (PVB), a heat activated adhesive usedextensively with optical films. The use of conventional adhesionenhancing techniques such as the use of surface treatments (for examplecorona or flame treatment) as well as the use of conventional primers,can sometimes improve the adhesion but they are not consistently useful.In particular, the non-suitability of a variety of conventional primerswill be discussed in detail below as well as in the Examples section.Therefore, a need for primers that are able to enhance the adhesion ofheat activated adhesives to polyester surfaces remains. In thisdisclosure, a class of polyurethane-based primers is described that aresuitable for use with a wide range of polyester surfaces and heatactivated adhesives. Additionally, because the polyurethane-basedprimers described herein can be applied so conveniently to polyestersurfaces, they can also be applied to polyester surfaces that do nothave heat activated adhesives applied to them to provide either enhancedadhesion of other types of coatings, or other properties. The primercoating can be advantageous even without the application of additionalcoatings because they can provide enhanced slipping over rollers andeasier winding and unwinding of film rolls.

Unless otherwise indicated, all numbers expressing feature sizes,amounts, and physical properties used in the specification and claimsare to be understood as being modified in all instances by the term“about” Accordingly, unless indicated to the contrary, the numericalparameters set forth in the foregoing specification and attached claimsare approximations that can vary depending upon the desired propertiessought to be obtained by those skilled in the art utilizing theteachings disclosed herein. The recitation of numerical ranges byendpoints includes all numbers subsumed within that range (e.g. 1 to 5includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within thatrange.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” encompass embodiments having pluralreferents, unless the content clearly dictates otherwise. For example,reference to “a layer” encompasses embodiments having one, two or morelayers. As used in this specification and the appended claims, the term“or” is generally employed in its sense including “and/or” unless thecontent clearly dictates otherwise.

The term “adhesive” as used herein refers to polymeric compositionsuseful to adhere together two adherends. Examples of adhesives are heatactivated adhesives and pressure sensitive adhesives.

Heat activated adhesives are non-tacky at room temperature but becometacky and capable of bonding to a substrate at elevated temperatures.These adhesives usually have a T_(g) (glass transition temperature) ormelting point (T_(m)) above room temperature. When the temperature iselevated above the T_(g) or T_(m), the storage modulus usually decreasesand the adhesive becomes tacky.

Pressure sensitive adhesive compositions are well known to those ofordinary skill in the art to possess properties including the following:(1) aggressive and permanent tack, (2) adherence with no more thanfinger pressure, (3) sufficient ability to hold onto an adherend, and(4) sufficient cohesive strength to be cleanly removable from theadherend. Materials that have been found to function well as pressuresensitive adhesives are polymers designed and formulated to exhibit therequisite viscoelastic properties resulting in a desired balance oftack, peel adhesion, and shear holding power. Obtaining the properbalance of properties is not a simple process.

The term “(meth)acrylate” refers to monomeric acrylic or methacrylicesters of alcohols. Acrylate and methacrylate monomers or oligomers arereferred to collectively herein as “(meth)acrylates”. Polymers describedas “(meth)acrylate-based” are polymers or copolymers prepared primarily(greater than 50% by weight) from (meth)acrylate monomers and mayinclude additional ethylenically unsaturated monomers.

Unless otherwise indicated, “optically transparent” refers to anarticle, film or adhesive composition that has a high lighttransmittance over at least a portion of the visible light spectrum(about 400 to about 700 nm). The term “transparent film” refers to afilm having a thickness and when the film is disposed on a substrate, animage (disposed on or adjacent to the substrate) is visible through thethickness of the transparent film. In many embodiments, a transparentfilm allows the image to be seen through the thickness of the filmwithout substantial loss of image clarity. In some embodiments, thetransparent film has a matte or glossy finish.

Unless otherwise indicated, “optically clear” refers to an adhesive orarticle that has a high light transmittance over at least a portion ofthe visible light spectrum (about 400 to about 700 nm), and thatexhibits low haze.

The term “urethane-based” as used herein refers to macromolecules thatare copolymers or segmented copolymers which contain at least oneurethane linkage. The urethane group has the general structure(—O—(CO)—NR—) where (CO) defines a carbonyl group C═O, and R is hydrogenor an alkyl group. The term “segmented copolymer” refers to a copolymerof linked segments, each segment constitutes primarily a singlestructural unit or type of repeating unit.

The term “adjacent” as used herein when referring to two layers meansthat the two layers are in proximity with one another with nointervening open space between them. They may be in direct contact withone another (e.g. laminated together) or there may be interveninglayers.

Disclosed herein are articles that include a substrate with a firstpolyester surface and a second polyester surface, a crosslinkedpolyurethane-based primer coated on the first polyester surface, and anoptically clear heat activated adhesive adjacent to the crosslinkedpolyurethane-based primer.

A wide range of substrates with a first and second polyester surface aresuitable. In some embodiments, the substrate comprises a singlepolyester film. In other embodiments, the substrate comprises a filmwith an exterior coating or layer of polyester. In still otherembodiments, the film comprises a multi-layer film with the exteriorfilm layers being polyester layers.

Examples of suitable polyester films, include a wide range of films thatincorporate polyester-containing polymers. Useful polyester polymersinclude, for example, polymers having terephthalate, isophthalate,and/or naphthalate comonomer units, e.g., polyethylene naphthalate(PEN), polyethylene terephthalate (PET) and copolymers and blendsthereof. Examples of other suitable polyester copolymers are provided inthe PCT Patent Publications WO 99/36262 and in WO 99/36248. A widevariety of suitable polyester materials, including amorphous polyesterresins, are commercially available under the tradename VITEL fromBostik, Middleton, Mass., such as VITEL 1070B, 1750B, and 3300B, andunder the tradename DYNAPOL from Evonik Degussa Corp., Parsippany, N.J.,such as DYNAPOL S1313, S1421, S1420, S1606 and S1611. Other suitablepolyester materials include polycarbonates, polyarylates, and othernaphthalate and terephthalate-containing polymers, such as, for example,polybutylene naphthalate (PBN), polypropylene naphthalate (PPN),polybutylene terephthalate (PBT), polypropylene terephthalate (PPT), andblends and copolymers of any of the above with each other, with otherpolyesters, or with non-polyester polymers. The polymer films cancontain multiple layers of the same or different polyester materials, orcan be comprised of one or more non-polyester layers (as describedbelow).

Examples of suitable films with an exterior coating or layer ofpolyester include multi-layer optical films with exterior polyester filmlayers. A wide variety of multi-layer optical films with exterior filmlayers that are polyester materials are suitable. These multi-layeroptical films may comprise any of a variety of materials includingpolyesters as well as layers that are not polyesters, as long as theexterior surfaces comprise polyester film layers. Examples of suitablematerials include polyesters such as polyethylene terephthalate,polyethylene naphthalate, copolyesters or polyester blends based onnaphthalene dicarboxylic acids; polycarbonates; polystyrenes;styrene-acrylonitriles; cellulose acetates; polyether sulfones;poly(meth)acrylates such as polymethylmethacrylate; polyurethanes;polyvinyl chloride; polycyclo-olefins; polyimides; glass; paper; orcombinations or blends thereof. Particular examples include polyethyleneterephthalate, polymethyl methacrylate, polyvinyl chloride, andcellulose triacetate. In some embodiments, the multi-layer optical filmcomprises polyethylene terephthalate, polyethylene naphthalate,cellulose triacetate, polypropylene, polyester, polycarbonate,polymethylmethacrylate, polyimide, polyamide, or a blend thereof.Generally, the multi-layer optical film is sufficiently resistant totemperature and aging such that performance of the article is notcompromised over time. The thickness of the multi-layer optical film istypically less than about 2.5 mm. The multi-layer optical film may alsobe an orientable film such as a cast web substrate that is coated beforeorientation in a tentering operation.

The multi-layer optical film is suitable for use in opticalapplications. Useful multi-layer optical films are designed to controlthe flow of light. They may have a transmission of greater than about90%, and a haze value of less than about 5%, for example, less than 2%,or less than 1%. Properties to consider when selecting a suitablemulti-layer optical film include mechanical properties such asflexibility, dimensional stability, self-supportability, and impactresistance. For example, the multi-layer optical film may need to bestructurally strong enough so that the article can be assembled as partof a display device.

The multi-layer optical film may be used in a wide variety ofapplications such as graphic arts and optical applications. A usefulmulti-layer optical film may be described as a reflective film, apolarizer film, a reflective polarizer film, a diffuse blend reflectivepolarizer film, a diffuser film, a brightness enhancing film, a turningfilm, a mirror film, or a combination thereof. The multi-layer opticalfilm may have ten or less layers, hundreds, or even thousands of layers,the layers being composed of some combination of all birefringentoptical layers, some birefringent optical layers, or all isotropicoptical layers. In one embodiment, the multi-layer optical film hasalternating layers of first and second optical layers, wherein the firstand second optical layers have refractive indices along at least oneaxis that differ by at least 0.04. Multi-layer optical films havingrefractive index mismatches are described in the references cited below.In another embodiment, the multi-layer optical film may comprise one ormore layers of any of the above multi-layer optical films such that theprimer layer is buried in any one of them, making the article itself areflective film, a polarizer film, a reflective polarizer film, adiffuse blend reflective polarizer film, a diffuser film, a brightnessenhancing film, a turning film, a mirror film, or a combination thereof.The optical film may contain a microstructured surface. In someembodiments, the optical film may contain a microstructured surface toredirect visible light.

Useful multi-layer optical films include commercially available opticalfilms marketed as VIKUITI Dual Brightness Enhanced Film (DBEF), VIKUITIBrightness Enhanced Film (BEF), VIKUITI Diffuse Reflective PolarizerFilm (DRPF), VIKUITI Enhanced Specular Reflector (ESR), and VIKUITIAdvanced Polarizing Film (APF), all available from 3M Company, St. Paul,Minn. Useful optical films are also described in U.S. Pat. No.5,825,543; U.S. Pat. No. 5,828,488 (Ouderkirk et al); U.S. Pat. No.5,867,316; U.S. Pat. No. 5,882,774; U.S. Pat. No. 6,179,948 B1 (Merrillet al); U.S. Pat. No. 6,352,761 B1; U.S. Pat. No. 6,368,699 B1; U.S.Pat. No. 6,927,900 B2; U.S. Pat. No. 6,827,886 (Neavin et al.); U.S.Pat. No. 6,972,813 B1 (Toyooka); U.S. Pat. No. 6,991,695; 2006/0084780A1 (Hebrink et al.); 2006/0216524 A1; 2006/0226561 A1 (Merrill et al.);2007/0047080 A1 (Stover et al.); WO 95/17303; WO 95/17691; WO95/17692;WO 95/17699; WO 96/19347; WO 97/01440; WO 99/36248; and WO99/36262.These multi-layer optical films are merely illustrative and are notmeant to be an exhaustive list of suitable multi-layer optical filmsthat can be used.

The articles of this disclosure also include a crosslinkedpolyurethane-based primer coated on the first polyester surface. In someembodiments, the crosslinked polyurethane-based primer is coated on bothpolyester surfaces. In other embodiments, the second polyester surfacecontains a surface treatment that is not a primer coating. Suchnon-primer surface treatments include, for example, flame treatments,plasma treatments, and corona treatments.

The primer on the first polyester surface is present to facilitateadhesion between the polyester film layer and the optically clear heatactivated adhesive layer. It has been observed that it is oftendifficult for heat activated adhesive layers to adhere well to polyesterfilms. In some instances, surface treatments such as corona, flame orplasma treatments can sufficiently alter the surface of the polyesterfilm that heat activated adhesives can adhere to them. However, it isfrequently the case that such surface treatments are either notsufficient to provide adequate adhesion or are ineffective to improveadhesion. Therefore, the polyurethane-based primers of this disclosurewere developed. The polyurethane-based primers comprise the reactionproduct of a polyurethane-based dispersion and a polyisocyanatecrosslinker.

The polyurethane-based dispersion consists of, consists primarily of, orat least comprises a solvent-based or a water-based polyurethane. Insome embodiments, the polyurethane is a polyester-based polyurethane, apolycarbonate-based polyurethane or a combination or blend of both. Thewater-based polyurethane can be made from an aqueous-based polyurethanedispersion (i.e., PUD), and the solvent-based polyurethane can be madefrom a solvent-based polyurethane solution (i.e., PUS). It may bedesirable to use PUDs, because of the elimination of the volatilesolvents typically associated with using PUSs. Particularly desirablePUDs are polycarbonate-based polyurethanes and polyester-basedpolyurethanes. Examples of particularly suitable PUDs are described inthe PCT Publication WO 2006/118883 (Ho et al.)

The polyurethane can be the reaction product of one or more polyolsegments and one or more diisocyanate segments. It may be desirable forone or more triisocyanate segments to be used with the diisocyanate. Itmay be desirable to use up to about 10%, based on the total weight ofthe reaction components, of triisocyanate segments with thediisocyanate. In some embodiments, the polyol is a polyester polyol, apolycarbonate polyol or a combination of both. It has also been founddesirable to use a diisocyanate such as, for example, isophoronediisocyanate, bis(4-isocyanato-cyclohexyl) methane or a combination ofboth.

The use of aliphatic materials in the present primer composition isgenerally desirable, particularly when the primer compositions are usedin applications such as window glazing applications. Examples ofsuitable materials include an aliphatic water-based polyurethane, analiphatic polycaprolactone-based thermoplastic polyurethane or both.Thus, in making the polyurethane, it can be desirable to use one or acombination of aliphatic polyols, aliphatic diisocyanates and aliphatictriisocyanates.

The polyurethane-based primers also comprise a crosslinker. Thecrosslinker may be a multi-functional isocyanate-functional material ora melamine formaldehyde crosslinker such as CYMEL 327 commerciallyavailable from Cytec Industries, Inc., Woodland Park, N.J. In manyembodiments, the crosslinkers are multifunctional isocyanate-functionalcompounds. The multifunctional isocyanate-functional compounds compriseat least two isocyanate groups (diisocyanates) and may contain more thantwo isocyanate groups (triisocyantes, tetraisocyanates, etc.). Examplesof suitable diisocyanates include, but are not limited to, aromaticdiisocyanates, such as 2,6-toluene diisocyanate, 2,5-toluenediisocyanate, 2,4-toluene diisocyanate, m-phenylene diisocyanate,p-phenylene diisocyanate, methylene bis(o-chlorophenyl diisocyanate),methylenediphenylene-4,4′-diisocyanate, polycarbodiimide-modifiedmethylenediphenylene diisocyanate,(4,4′-diisocyanato-3,3′,5,5′-tetraethyl) biphenylmethane,4,4′-diisocyanato-3,3′-dimethoxybiphenyl, 5-chloro-2,4-toluenediisocyanate, 1-chloromethyl-2,4-diisocyanato benzene,aromatic-aliphatic diisocyanates such as m-xylylene diisocyanate,tetramethyl-m-xylylene diisocyanate, aliphatic diisocyanates, such as1,4-diisocyanatobutane, 1,6-diisocyanatohexane,1,12-diisocyanatododecane, 2-methyl-1,5diisocyanatopentane, andcycloaliphatic diisocyanates such asmethylene-dicyclohexylene-4,4′-diisocyanate, and3-isocyanatomethyl-3,5,5-trimethyl-cyclohexyl isocyanate (isophoronediisocyanate).

Suitable tri-isocyanates include aliphatic and aromatic triisocyanatesand examples of such compounds include the aliphatic triisocyanate1,3,6-hexamethylenetriisocyanate, and the aromatic tri-isocyanatepolymethylenepolyphenylisocyanate (PAPI).

Also useful are isocyanates that contain internal, isocyanate-derivedmoieties such as biuret-containing tri-isocyanates (e.g., DESMODURN-100, available from Bayer), isocyanurate-containing tri-isocyanates(e.g., IPDI-1890 available from Huls AG, Germany), andazetedinedione-containing diisocyanates (e.g., DESMODUR TT availablefrom Bayer). Also suitable are other di- or tri-isocyanates such asDESMODUR L and DESMODUR W (both available from Bayer), andtri-(4-isocyanatophenyl)-methane (available from Bayer as DESMODUR R).

Typically, the polyisocyanate crosslinker comprises an aliphaticdiisocyanate, a blocked isocyanate, or a combination thereof.Particularly suitable polyisocyanate crosslinkers are the aliphaticisocyanate crosslinkers commercially available from Bayer MaterialScience under the trade name “BAYHYDOR”, such as BAYHYDOR 303, BAYHYDOR305, BAYHYDOR 401-70, BAYHYDOR XP2487/1, and BAYHYDOR XP7165, and thoseavailable from Perstorp Polyols, Inc. Toledo, Ohio under the trade name“ESAQUA” such as ESAQUA XD 401, and ESAQUA XM 501.

Examples of suitable blocked isocyanates include those commerciallyavailable from Bayer Material Science under the trade names BAYHYDORVPLS 2310, and BAYHYDOR BL 5335, as well as those available fromBaxenden Chemicals Limited under the trade names TRIXENE B1 7986, andTRIXENE B1 7987.

A wide variety of optically clear heat activated adhesives can be usedin conjunction with the polyurethane-based primers described above.Examples of suitable optically clear heat activated adhesives includepolyacrylate hot melt adhesives, polyvinyl butyrals, ethylene vinylacetate, ionomers, polyolefins, or combinations thereof.

The optically clear heat activated adhesives may be (meth)acrylate-basedhot melt adhesives. The hot melt adhesives typically are prepared from(meth)acrylate polymers that have a glass transition temperature (Tg) ofgreater than room temperature, more typically greater than about 40° C.,and are prepared from alkyl(meth)acrylate monomers. Usefulalkyl(meth)acrylates (i.e., acrylic acid alkyl ester monomers) includelinear or branched monofunctional unsaturated acrylates or methacrylatesof non-tertiary alkyl alcohols, the alkyl groups of which have from 4 to14 and, in particular, from 4 to 12 carbon atoms. Poly(meth)acrylic hotmelt adhesives may also contain optional co-monomer components such as,for example, (meth)acrylic acid, vinyl acetate, N-vinyl pyrrolidone,(meth)acrylamide, a vinyl ester, a fumarate, a styrene macromer, alkylmaleates and alkyl fumarates (based, respectively, on maleic and fumaricacid), or combinations thereof.

In some embodiments, the adhesive layer is at least partially formed ofpolyvinyl butyral. The polyvinyl butyral layer may be formed via knownaqueous or solvent-based acetalization process in which polyvinylalcohol is reacted with butyraldehyde in the presence of an acidiccatalyst. In some instances, the polyvinyl butyral layer may include orbe formed from polyvinyl butyral that is commercially available fromSolutia Incorporated, of St. Louis, Mo., under the trade name “BUTVAR”resin.

In some instances, the polyvinyl butyral layer may be produced by mixingresin and (optionally) plasticizer and extruding the mixed formulationthrough a sheet die. If a plasticizer is included, the polyvinyl butyralresin may include about 20 to 80 or perhaps about 25 to 60 parts ofplasticizer per hundred parts of resin. Examples of suitableplasticizers include esters of a polybasic acid or a polyhydric alcohol.Suitable plasticizers are triethylene glycol bis(2-ethylbutyrate),triethylene glycol di-(2-ethylhexanoate), triethylene glycoldiheptanoate, tetraethylene glycol diheptanoate, dihexyl adipate,dioctyl adipate, hexyl cyclohexyl adipate, mixtures of heptyl and nonyladipates, diisononyl adipate, heptylnonyl adipate, dibutyl sebacate,polymeric plasticizers such as the oil-modified sebacic alkyds, andmixtures of phosphates and adipates such as disclosed in U.S. Pat. No.3,841,890 and adipates such as disclosed in U.S. Pat. No. 4,144,217.

Examples of suitable ethylene vinyl acetate (EVA) adhesives include awide range of commercially available EVA hot melt adhesives. Typicallythese EVA hot melt adhesives have a vinyl acetate content of from about18-29% by weight of the polymer. The adhesives typically have highamounts of tackifiers and waxes. An exemplary composition is one with30-40% by weight of EVA polymer, 30-40% by weight of tackifier, 20-30%by weight of wax, and 0.5-1% by weight of stabilizers. Examples ofsuitable EVA hot melt adhesives are the BYNEL SERIES 3800 resinscommercially available from DuPont, Wilmington, Del. (including BYNEL3810, BYNEL 3859, BYNEL 3860, and BYNEL 3861). A particularly suitableEVA hot melt adhesive is the material available from Bridgestone Corp.Tokyo, JP under the trade name “EVASAFE”.

Examples of suitable ionomeric adhesives are the “ionoplast resins”.Ionoplast resins are copolymers of ethylene and unsaturated carboxylicacids, wherein at least a portion of the acid groups in the copolymerhave been neutralized to the salt form of the acid. Extruded sheets ofionoplast resins suitable for use in this disclosure are commerciallyavailable from DuPont Chemicals, Wilmington, Del., under the trade name“SENTRYGLASS PLUS”.

Examples of suitable polyolefin adhesives include ethylene/α-olefincopolymers. As used herein, the term “ethylene/α-olefin copolymer”refers to polymers comprising a class of hydrocarbons manufactured bythe catalytic oligomerization (i.e., polymerization tolow-molecular-weight products) of ethylene and linear α-olefin monomers.The ethylene/α-olefin copolymers may be made, for example, with a singlesite catalyst such as a metallocene catalyst or multi-site catalystssuch as Ziegler-Natta and Phillips catalysts. The linear α-olefinmonomers typically are 1-butene or 1-octene but may range from C3 to C20linear, branched or cyclic α-olefin. The α-olefin may be branched butonly if the branch is at least alpha to the double bond, such as3-methyl-1-pentene. Examples of C3-C20 α-olefins include propylene,1-butene, 4-methyl-1-butene, 1-hexene, 1-octene, 1-dodecene,1-tetradecene, 1-hexadecene and 1-octadecene. The α-olefins can alsocontain a cyclic structure such as cyclohexane or cyclopentane,resulting in an α-olefin such as 3-cyclohexyl-1 propene (allylcyclohexane) and vinyl cyclohexane. Although not α-olefins in theclassical sense of the term, for purposes of this disclosure certaincyclic olefins, such as norbornene and related olefins, are α-olefinsand can be used. Similarly, styrene and its related olefins (forexample, α-methyl styrene) are α-olefins for the purposes of thisdisclosure. Acrylic and methacrylic acid and their respective ionomers,and acrylates and methacrylates, however are not α-olefins for thepurposes of this disclosure. Illustrative ethylene/α-olefin copolymersinclude ethylene/1-butene, ethylene/l-octene,ethylene/1-butene/1-octene, ethylene/styrene. The polymers can be blockor random. Exemplary commercially available low crystallineethylene/α-olefin copolymers include resins sold under the tradenames“ENGAGE” ethylene/1-butene and ethylene/1-octene copolymers and“FLEXOMER” ethylene/1-hexene copolymer, available from Dow Chemical Co.,and homogeneously branched, substantially linear ethylene/α-olefincopolymers such as “TAFMER”, available from Mitsui PetrochemicalsCompany Limited, and “EXACT”, available from ExxonMobil Corp. As usedherein, the term “copolymer” refers to polymers made from at least 2monomers.

In some of these embodiments, the α-olefin moiety of theethylene/α-olefin copolymer includes four or more carbons. In someembodiments, the ethylene/α-olefin copolymer is a low crystallineethylene/α-olefin copolymer. As used herein, the term “low crystalline”means crystallinity (according to method disclosed in ASTM F2625-07) ofless than 50% by weight. In some embodiments, the low crystallineethylene/α-olefin copolymer is a butene α-olefin. In some embodimentsthe α-olefin of the low crystalline ethylene/α-olefin copolymer has 4 ormore carbons.

In some embodiments, the low crystalline ethylene/α-olefin copolymer hasa DSC peak melting point of less than or equal to 50° C. As used herein,the term “DSC peak melting point” means a melting point determined byDSC (10°/min) under nitrogen purge as the peak with the largest areaunder the DSC curve.

As described above, the articles of this disclosure may also comprise acrosslinked polyurethane-based primer coated on the second polyestersurface of the substrate. This crosslinked polyurethane-based primer maybe the same as the crosslinked polyurethane-based primer coated on thefirst polyester surface of the substrate or it may be different.Typically, the crosslinked polyurethane-based primers are the same forease of applying and handling. Suitable crosslinked polyurethane-basedprimers are described in detail above.

As with the first polyester surface of the substrate, the crosslinkedpolyurethane-based primer coating on the second polyester surface of thesubstrate may also have a layer adjacent to the crosslinkedpolyurethane-based primer coating. This layer may comprise an opticallyclear heat activated adhesive layer, a cured hardcoat layer, an opticallayer, or a pressure sensitive adhesive layer.

Optically clear heat activated adhesives are described in detail above.If the layer adjacent to the crosslinked polyurethane-based primercoating on the second polyester surface of the substrate is an opticallyclear heat activated adhesive, it may the same as or different from theoptically clear heat activated adhesive adjacent to the crosslinkedpolyurethane-based primer coating on the first polyester surface of thesubstrate.

In some embodiments, it may be desirable that the second polyestersurface contain a layer other than an optically clear heat activatedadhesive, such as a cured hardcoat layer, an optical layer or a pressuresensitive adhesive layer.

Hardcoats are coatings placed on surfaces generally to provideprotection such as abrasion and graffiti resistance. Typically, thehardcoat surfaces are optically transparent. The hardcoat layer can bemade from any suitably curable polymeric material. As used herein,“polymeric material” will be understood to include polymers, copolymers(for example, polymers formed using two or more different monomers),oligomers, and combinations thereof, as well as polymers, copolymers, oroligomers that can be formed in a miscible blend. An example of asuitable material for the hardcoat layer is a multifunctional orcross-linkable monomer. Examples of suitable hardcoat layers includethose described in US Patent Publication No. 2009/0000727 (Kumar etal.).

Examples of cross-linkable monomers include multifunctional acrylates,urethanes, urethane acrylates, siloxanes, and epoxies. In someembodiments, cross-linkable monomers include mixtures of multifunctionalacrylates, urethane acrylates, or epoxies.

Useful acrylates include, for example, poly(meth)acryl monomers such as,for example, di(meth)acryl containing compounds, tri(meth)acrylcontaining compounds, higher functionality (meth)acryl containingcompounds and oligomeric(meth)acryl compounds.

Suitable di(meth)acryl containing compounds include 1,3-butylene glycoldiacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate,1,6-hexanediol monoacrylate monomethacrylate, ethylene glycoldiacrylate, alkoxylated aliphatic diacrylate, alkoxylated cyclohexanedimethanol diacrylate, alkoxylated hexanediol diacrylate, alkoxylatedneopentyl glycol diacrylate, caprolactone modified neopentylglycolhydroxypivalate diacrylate, caprolactone modified neopentylglycolhydroxypivalate diacrylate, cyclohexanedimethanol diacrylate, diethyleneglycol diacrylate, dipropylene glycol diacrylate, ethoxylated (10)bisphenol A diacrylate, ethoxylated (3) bisphenol A diacrylate,ethoxylated (30) bisphenol A diacrylate, ethoxylated (4) bisphenol Adiacrylate, hydroxypivalaldehyde modified trimethylolpropane diacrylate,neopentyl glycol diacrylate, polyethylene glycol (200) diacrylate,polyethylene glycol (400) diacrylate, polyethylene glycol (600)diacrylate, propoxylated neopentyl glycol diacrylate, tetraethyleneglycol diacrylate, tricyclodecanedimethanol diacrylate, triethyleneglycol diacrylate, and tripropylene glycol diacrylate.

Suitable tri(meth)acryl containing compounds include glyceroltriacrylate, trimethylolpropane triacrylate, ethoxylated triacrylates(for example, ethoxylated (3) trimethylolpropane triacrylate,ethoxylated (6) trimethylolpropane triacrylate, ethoxylated (9)trimethylolpropane triacrylate, ethoxylated (20) trimethylolpropanetriacrylate), pentaerythritol triacrylate, propoxylated triacrylates(for example, propoxylated (3) glyceryl triacrylate, propoxylated (5.5)glyceryl triacrylate, propoxylated (3) trimethylolpropane triacrylate,propoxylated (6) trimethylolpropane triacrylate), trimethylolpropanetriacrylate, pentaerythritol triacrylate, andtris(2-hydroxyethyl)isocyanurate triacrylate.

Suitable higher functionality (meth)acryl containing compounds includeditrimethylolpropane tetraacrylate, dipentaerythritol pentaacrylate,ethoxylated (4) pentaerythritol tetraacrylate, pentaerythritoltetraacrylate, and caprolactone modified dipentaerythritol hexaacrylate.

Suitable oligomeric(meth)acryl compounds include urethane acrylates,polyester acrylates, epoxy acrylates; polyacrylamide analogues of theforegoing such as, for example, N,N-dimethyl acrylamide; andcombinations thereof.

Many poly(meth)acryl monomers are widely available from vendors such as,for example, Sartomer Company, Exton, Pa.; UCB Chemicals Corporation,Smyrna, Ga.; and Aldrich Chemical Company, Milwaukee, Wis. Additionaluseful (meth)acrylate materials include hydantoin moiety-containingpoly(meth)acrylates, for example, as described in U.S. Pat. No.4,262,072 (Wendling et al.).

In an illustrative embodiment, the hardcoat layer includes a monomerhaving at least two or three (meth)acrylate functional groups.Commercially available cross-linkable acrylate monomers include thoseavailable from Sartomer Company, Exton, Pa. such as trimethylolpropanetriacrylate available under the trade designation SR351, pentaerythritoltriacrylate available under the trade designation SR444,dipentaerythritol triacrylate available under the trade designationSR399LV, ethoxylated (3) trimethylolpropane triacrylate available underthe trade designation SR454, ethoxylated (4) pentaerythritoltriacrylate, available under the trade designation SR494,tris(2-hydroxyethyl)isocyanurate triacrylate, available under the tradedesignation SR368, and dipropylene glycol diacrylate, available underthe trade designation SR508.

Useful urethane acrylate monomers include, for example, a hexafunctionalurethane acrylate available as EBECRYL 8301 from Radcure UCB Chemicals(Smyrna, Ga.), CN981 and CN981B88 available from Sartomer Company(Exton, Pa.), and a difunctional urethane acrylate available as EBECRYL8402 from Radcure UCB Chemicals. In some embodiments the hardcoat layerresin includes both poly(meth)acrylate and polyurethane material, whichcan be termed a “urethane acrylate.”

In some embodiments, the hardcoat layer can include a plurality ofinorganic nanoparticles. The inorganic nanoparticles can include, forexample, silica, alumina, or zirconia (the term “zirconia” includeszirconia metal oxide) nanoparticles. In some embodiments, thenanoparticles have a mean diameter in a range from 1 to 200 nm, or 5 to150 nm, or 5 to 125 nm. Nanoparticles can be present in an amount from10 to 200 parts per 100 parts of hardcoat layer monomer.

Useful silica nanoparticles are commercially available from NalcoChemical Co. (Naperville, Ill.) under the product designation NALCOCOLLOIDAL SILICAS. For example, silicas include NALCO products 1040,1042, 1050, 1060, 2327 and 2329. Useful zirconia nanoparticles arecommercially available from Nalco Chemical Co. (Naperville, Ill.) underthe product designation NALCO OOSSOO8.

Surface treating or surface modification of the nanoparticles canprovide a stable dispersion in the hardcoat layer resin. Thesurface-treatment can stabilize the nanoparticles so that the particleswill be well dispersed in the polymerizable resin and result in asubstantially homogeneous composition. Furthermore, the nanoparticlescan be modified over at least a portion of its surface with a surfacetreatment agent so that the stabilized particle can copolymerize orreact with the polymerizable hardcoat layer resin during curing.

A photoinitiator can be included in the hardcoat layer. Examples ofinitiators include organic peroxides, azo compounds, quinines, nitrocompounds, acyl halides, hydrazones, mercapto compounds, pyryliumcompounds, imidazoles, chlorotriazines, benzoin, benzoin alkyl ethers,di-ketones, phenones, and the like. Commercially availablephotoinitiators include those available commercially from Ciba Geigyunder the trade designations DAROCUR 1173, DAROCUR 4265, IRGACURE 651,IRGACURE 184, IRGACURE 1800, IRGACURE 369, IRGACURE 1700, IRGACURE 907,IRGACURE 819 and from Aceto Corp. (Lake Success, N.Y.) under the tradedesignations UV1-6976 and UV1-6992.Phenyl-[p-(2-hydroxytetradecyloxyl)phenyl]iodonium hexafluoroantomonateis a photoinitiator commercially available from Gelest (Tullytown, Pa.).Phosphine oxide derivatives include LUCIRIN TPO, which is2,4,6-trimethylbenzoy diphenyl phosphine oxide, available from BASF(Charlotte, N.C). In addition, further useful photoinitiators aredescribed in U.S. Pat. Nos. 4,250,311, 3,708,296, 4,069,055, 4,216,288,5,084,586, 5,124,417, 5,554,664, and 5,672,637. A photoinitiator can beused at a concentration of about 0.1 to 10 weight percent or about 0.1to 5 weight percent based on the organic portion of the formulation(phr).

Examples of optical layers include virtually any layer that is used tocontrol light. These include a wide array of optical films as well ascoating layers. As used herein, the term “optical film” refers to a filmthat can be used to produce an optical effect. The optical films aretypically polymer-containing films that can be a single layer ormultiple layers. The optical films are flexible and can be of anysuitable thickness. The optical films often are at least partiallytransmissive, reflective, antireflective, polarizing, optically clear,or diffusive with respect to some wavelengths of the electromagneticspectrum (e.g., wavelengths in the visible ultraviolet, or infraredregions of the electromagnetic spectrum). Exemplary optical filmsinclude, but are not limited to, visible mirror films, color mirrorfilms, solar reflective films, infrared reflective films, ultravioletreflective films, reflective polarizer films such as a brightnessenhancement films and dual brightness enhancement films, absorptivepolarizer films, optically clear films, tinted films, and antireflectivefilms. The optical film may contain a microstructured surface. In someembodiments, the optical film may contain a microstructured surface toredirect visible light.

In some embodiments the optical layer may be a coating or may include anoptical film that has a coating. In general, coatings are used toenhance the function of the film or provide additional functionality tothe film. Examples of coatings include, for example, hardcoats (asdescribed above), anti-fog coatings, anti-scratch coatings, privacycoatings or a combination thereof. Coatings such as hardcoats, anti-fogcoatings, and anti-scratch coatings that provide enhanced durability.Examples of privacy coatings include, for example, blurry or hazycoatings to give obscured viewing or louvered films to limit the viewingangle.

Suitable pressure sensitive adhesives include those based on naturalrubbers, synthetic rubbers, styrene block copolymers, polyvinyl ethers,acrylics, poly-α-olefins, silicones, urethanes or ureas.

Useful natural rubber pressure sensitive adhesives generally containmasticated natural rubber, from 25 parts to 300 parts of one or moretackifying resins to 100 parts of natural rubber, and typically from 0.5to 2.0 parts of one or more antioxidants. Natural rubber may range ingrade from a light pale crepe grade to a darker ribbed smoked sheet andincludes such examples as CV-60, a controlled viscosity rubber grade andSMR-5, a ribbed smoked sheet rubber grade.

Tackifying resins used with natural rubbers generally include but arenot limited to wood rosin and its hydrogenated derivatives; terpeneresins of various softening points, and petroleum-based resins, such as,the “ESCOREZ 1300” series of C5 aliphatic olefin-derived resins fromExxon, and “PICCOLYTE S” series, polyterpenes from Hercules, Inc.Antioxidants are used to retard the oxidative attack on natural rubber,which can result in loss of the cohesive strength of the natural rubberadhesive. Useful antioxidants include but are not limited to amines,such as N—N′ di-β-naphthyl-1,4-phenylenediamine, available as “AGERITED”; phenolics, such as 2,5-di-(t-amyl) hydroquinone, available as“SANTOVAR A”, available from Monsanto Chemical Co., tetrakis[methylene3-(3′,5′-di-tert-butyl-4′-hydroxyphenyl)propianate]methane, available as“IRGANOX 1010” from Ciba-Geigy Corp., and2-2′-methylenebis(4-methyl-6-tert butyl phenol), available asAntioxidant 2246; and dithiocarbamates, such as zinc dithiodibutylcarbamate. Other materials can be added to natural rubber adhesives forspecial purposes, wherein the additions can include plasticizers,pigments, and curing agents to partially vulcanize the pressuresensitive adhesive.

Another useful class of pressure sensitive adhesives are thosecomprising synthetic rubber. Such adhesives are generally rubberyelastomers, which are either self-tacky or non tacky and requiretackifiers.

Self-tacky synthetic rubber pressure sensitive adhesives include forexample, butyl rubber, a copolymer of isobutylene with less than 3percent isoprene, polyisobutylene, a homopolymer of isoprene,polybutadiene, such as “TAKTENE 220 BAYER” or styrene/butadiene rubber.Butyl rubber pressure sensitive adhesives often contain an antioxidantsuch as zinc dibutyl dithiocarbamate. Polyisobutylene pressure sensitiveadhesives do not usually contain antioxidants. Synthetic rubber pressuresensitive adhesives, which generally require tackifiers, are alsogenerally easier to melt process. They comprise polybutadiene orstyrene/butadiene rubber, from 10 parts to 200 parts of a tackifier, andgenerally from 0.5 to 2.0 parts per 100 parts rubber of an antioxidantsuch as “IRGANOX 1010”. An example of a synthetic rubber is “AMERIPOL1011A”, a styrene/butadiene rubber available from BF Goodrich.Tackifiers that are useful include derivatives of rosins such as “FORAL85”, a stabilized rosin ester from Hercules, Inc., the “SNOWTACK” seriesof gum rosins from Tenneco, and the “AQUATAC” series of tall oil rosinsfrom Sylvachem; and synthetic hydrocarbon resins such as the “PICCOLYTEA” series, polyterpenes from Hercules, Inc., the “ESCOREZ 1300” seriesof C₅ aliphatic olefin-derived resins, the “ESCOREZ 2000” Series of C₉aromatic/aliphatic olefin-derived resins, and polyaromatic C₉ resins,such as the “PICCO 5000” series of aromatic hydrocarbon resins, fromHercules, Inc. Other materials can be added for special purposes,including hydrogenated butyl rubber, pigments, plasticizers, liquidrubbers, such as “VISTANEX LMMH” polyisobutylene liquid rubber availablefrom Exxon, and curing agents to vulcanize the adhesive partially.

Styrene block copolymer pressure sensitive adhesives generally compriseelastomers of the A-B or A-B-A type, where A represents a thermoplasticpolystyrene block and B represents a rubbery block of polyisoprene,polybutadiene, or poly(ethylene/butylene), and resins. Examples of thevarious block copolymers useful in block copolymer pressure sensitiveadhesives include linear, radial, star and tapered styrene-isopreneblock copolymers such as “KRATON D1107P”, available from Shell ChemicalCo., and “EUROPRENE SOL TE 9110”, available from EniChem ElastomersAmericas, Inc.; linear styrene-(ethylene-butylene) block copolymers suchas “KRATON G1657”, available from Shell Chemical Co.; linearstyrene-(ethylene-propylene) block copolymers such as “KRATON G1750X”,available from Shell Chemical Co.; and linear, radial, and starstyrene-butadiene block copolymers such as “KRATON D1118X”, availablefrom Shell Chemical Co., and “EUROPRENE SOL TE 6205”, available fromEniChem Elastomers Americas, Inc. The polystyrene blocks tend to formdomains in the shape of spheroids, cylinders, or plates that causes theblock copolymer pressure sensitive adhesives to have two phasestructures. Resins that associate with the rubber phase generallydevelop tack in the pressure sensitive adhesive. Examples of rubberphase associating resins include aliphatic olefin-derived resins, suchas the “ESCOREZ 1300” series and the “WINGTACK” series, available fromGoodyear; rosin esters, such as the “FORAL” series and the “STAYBELITE”Ester 10, both available from Hercules, Inc.; hydrogenated hydrocarbons,such as the “ESCOREZ 5000” series, available from Exxon; polyterpenes,such as the “PICCOLYTE A” series; and terpene phenolic resins derivedfrom petroleum or terpentine sources, such as “PICCOFYN A100”, availablefrom Hercules, Inc. Resins that associate with the thermoplastic phasetend to stiffen the pressure sensitive adhesive. Thermoplastic phaseassociating resins include polyaromatics, such as the “PICCO 6000”series of aromatic hydrocarbon resins, available from Hercules, Inc.;coumarone-indene resins, such as the “CUMAR” series, available fromNeville; and other high-solubility parameter resins derived from coaltar or petroleum and having softening points above about 85° C., such asthe “AMOCO 18” series of alphamethyl styrene resins, available fromAmoco, “PICCOVAR 130” alkyl aromatic polyindene resin, available fromHercules, Inc., and the “PICCOTEX” series of alphamethyl styrene/vinyltoluene resins, available from Hercules. Other materials can be addedfor special purposes, including rubber phase plasticizing hydrocarbonoils, such as, “TUFFLO 6056”, available from Lydondell PetrochemicalCo., Polybutene-8 from Chevron, “KAYDOL”, available from Witco, and“SHELLFLEX 371”, available from Shell Chemical Co.; pigments;antioxidants, such as “IRGANOX 1010” and “IRGANOX 1076”, both availablefrom Ciba-Geigy Corp., “BUTAZATE”, available from Uniroyal Chemical Co.,“CYANOX LDTP”, available from American Cyanamid, and “BUTASAN”,available from Monsanto Co.; antiozonants, such as “NBC”, a nickeldibutyldithiocarbamate, available from DuPont; liquid rubbers such as“VISTANEX LMMH” polyisobutylene rubber; and ultraviolet lightinhibitors, such as “IRGANOX 1010” and “TINUVIN P”, available fromCiba-Geigy Corp.

Polyvinyl ether pressure sensitive adhesives are generally blends ofhomopolymers of vinyl methyl ether, vinyl ethyl ether or vinyl iso-butylether, or blends of homopolymers of vinyl ethers and copolymers of vinylethers and acrylates to achieve desired pressure sensitive properties.Depending on the degree of polymerization, homopolymers may be viscousoils, tacky soft resins or rubber-like substances. Polyvinyl ethers usedas raw materials in polyvinyl ether adhesives include polymers based on:vinyl methyl ether such as “LUTANOL M 40”, available from BASF, and“GANTREZ M 574” and “GANTREZ 555”, available from ISP Technologies,Inc.; vinyl ethyl ether such as “LUTANOL A 25”, “LUTANOL A 50” and“LUTANOL A 100”; vinyl isobutyl ether such as “LUTANOL 130”, “LUTANOL160”, “LUTANOL IC”, “LUTANOL 160D” and “LUTANOL I 65D”;methacrylate/vinyl isobutyl ether/acrylic acid such as “ACRONAL 550 D”,available from BASF. Antioxidants useful to stabilize the polyvinyletherpressure sensitive adhesive include, for example, “IONOX 30” availablefrom Shell, “IRGANOX 1010” available from Ciba-Geigy, and antioxidant“ZKF” available from Bayer Leverkusen. Other materials can be added forspecial purposes as described in BASF literature including tackifier,plasticizer and pigments.

Acrylic pressure sensitive adhesives generally have a glass transitiontemperature of about −20° C. or less and may comprise from 100 to 80weight percent of a C₃-C₁₂ alkyl ester component such as, for example,isooctyl acrylate, 2-ethyl-hexyl acrylate and n-butyl acrylate and from0 to 20 weight percent of a polar component such as, for example,acrylic acid, methacrylic acid, ethylene vinyl acetate, N-vinylpyrrolidone and styrene macromer. Generally, the acrylic pressuresensitive adhesives comprise from 0 to 20 weight percent of acrylic acidand from 100 to 80 weight percent of isooctyl acrylate. The acrylicpressure sensitive adhesives may be self-tacky or tackified. Usefultackifiers for acrylics are rosin esters such as “FORAL 85”, availablefrom Hercules, Inc., aromatic resins such as “PICCOTEX LC-55WK”,aliphatic resins such as “PICCOTAC 95”, available from Hercules, Inc.,and terpene resins such as α-pinene and β-pinene, available as“PICCOLYTE A-115” and “ZONAREZ B-100” from Arizona Chemical Co. Othermaterials can be added for special purposes, including hydrogenatedbutyl rubber, pigments, and curing agents to vulcanize the adhesivepartially.

Poly-α-olefin pressure sensitive adhesives, also called a poly(l-alkene)pressure sensitive adhesives, generally comprise either a substantiallyuncrosslinked polymer or a uncrosslinked polymer that may have radiationactivatable functional groups grafted thereon as described in U.S. Pat.No. 5,209,971 (Babu, et al) which is incorporated herein by reference.The poly-α-olefin polymer may be self tacky and/or include one or moretackifying materials. If uncrosslinked, the inherent viscosity of thepolymer is generally between about 0.7 and 5.0 dL/g as measured by ASTMD 2857-93, “Standard Practice for Dilute Solution Viscosity ofPolymers”. In addition, the polymer generally is predominantlyamorphous. Useful poly-α-olefin polymers include, for example, C₃-C₁₈poly(l-alkene) polymers, generally C₅-C₁₂ α-olefins and copolymers ofthose with C₃ or C₆-C₈ and copolymers of those with C₃. Tackifyingmaterials are typically resins that are miscible in the poly-α-olefinpolymer. The total amount of tackifying resin in the poly-α-olefinpolymer ranges between 0 to 150 parts by weight per 100 parts of thepoly-α-olefin polymer depending on the specific application. Usefultackifying resins include resins derived by polymerization of C₅ to C₉unsaturated hydrocarbon monomers, polyterpenes, synthetic polyterpenesand the like. Examples of such commercially available resins based on aC₅ olefin fraction of this type are “WINGTACK 95” and “WINGTACK 15”tackifying resins available from Goodyear Tire and Rubber Co. Otherhydrocarbon resins include “REGALREZ 1078” and “REGALREZ 1126” availablefrom Hercules Chemical Co., and “ARKON P115” available from ArakawaChemical Co. Other materials can be added for special purposes,including antioxidants, fillers, pigments, and radiation activatedcrosslinking agents.

Silicone pressure sensitive adhesives comprise two major components, apolymer or gum, and a tackifying resin. The polymer is typically a highmolecular weight polydimethylsiloxane or polydimethyldiphenylsiloxane,that contains residual silanol functionality (SiOH) on the ends of thepolymer chain, or a block copolymer comprising polydiorganosiloxane softsegments and urea terminated hard segments. The tackifying resin isgenerally a three-dimensional silicate structure that is endcapped withtrimethylsiloxy groups (OSiMe₃) and also contains some residual silanolfunctionality. Examples of tackifying resins include SR 545, fromGeneral Electric Co., Silicone Resins Division, Waterford, N.Y., andMQD-32-2 from Shin-Etsu Silicones of America, Inc., Torrance, Calif.Manufacture of typical silicone pressure sensitive adhesives isdescribed in U.S. Pat. No. 2,736,721 (Dexter). Manufacture of siliconeurea block copolymer pressure sensitive adhesive is described in U.S.Pat. No. 5,214,119 (Leir, et al). Other materials can be added forspecial purposes, including, pigments, plasticizers, and fillers.Fillers are typically used in amounts from 0 parts to 10 parts per 100parts of silicone pressure sensitive adhesive. Examples of fillers thatcan be used include zinc oxide, silica, carbon black, pigments, metalpowders and calcium carbonate.

Useful polyurethane and polyurea pressure sensitive adhesives usefulinclude, for example, those disclosed in WO 00/75210 (Kinning et al.)and in U.S. Pat. No. 3,718,712 (Tushaus); U.S. Pat. No. 3,437,622(Dahl); and U.S. Pat. No. 5,591,820 (Kydonieus et al.).

Also disclosed are articles that include a substrate with a firstpolyester surface and a second polyester surface, a crosslinkedpolyurethane-based primer coated on the first polyester surface, and apressure sensitive adhesive layer adjacent to the crosslinkedpolyurethane-based primer, instead of a heat activated adhesive.Examples of suitable pressure sensitive adhesives include thosedescribed above.

As with the articles described above, the second polyester surface ofthe substrate may also comprise a crosslinked polyurethane-based primercoating. This crosslinked polyurethane-based primer may be the same asthe crosslinked polyurethane-based primer coated on the first polyestersurface of the substrate or it may be different. Typically, thecrosslinked polyurethane-based primers are the same for ease of applyingand handling. Suitable crosslinked polyurethane-based primers aredescribed in detail above.

The film articles described above that comprise a substrate with a firstpolyester surface and a second polyester surface and crosslinkedpolyurethane-based primers coated on the first and second polyestersurfaces can be used to prepare laminate articles. In these laminatearticles the film articles are adhered to a glazing substrate.

A wide variety of glazing substrates are suitable in the laminatearticles of this disclosure. In some embodiments, a single glazingsubstrate is present, in other embodiments, multiple glazing substratesare present. In some embodiments the primed film articles describedabove are attached to an exterior surface of a glazing substrate, and inother embodiments, the primed film articles described above are locatedbetween two glazing substrates.

Suitable glazing substrates are at least optically transparent, and maybe optically clear. Examples of suitable substrates include, forexample, windows. Windows may be made of a variety of different types ofglazing substrates such as a variety of glasses or from polymericmaterials such as polycarbonate or polymethyl methacrylate. In someembodiments, the window may also comprise additional layers ortreatments. Examples of additional layers include, for example,additional layers of film designed to provide tinting, shatterresistance and the like. Examples of additional treatments that may bepresent of windows include, for example, coatings or various types suchas hardcoats, and etchings such as decorative etchings.

In some embodiments, both the first and second crosslinkedpolyurethane-based primer coatings have optically clear heat activatedadhesive layers adjacent to the primer coating. In other embodiments,one of polyurethane-based primer coatings has an optically clear heatactivated adhesive layer adjacent to the primer coating and the otherpolyurethane-based primer coating has a layer adjacent to the primerlayer. The layer may be a cured hardcoat, an optical layer, or apressure sensitive adhesive, as described above. Articles with twolayers of optically clear heat activated adhesive or a layer ofoptically clear heat activated adhesive and a layer of pressuresensitive adhesive, can be used to prepare sandwich laminates, i.e.where the film article is between two glazing substrates.

Typically the laminates have desirable optical properties such as highluminous transmission and low haze. Often the laminates of thisdisclosure have a luminous transmission of at least about 90 percent anda haze of less than about 3 percent in the 400 to 700 nm wavelengthrange. Both the luminous transmission and the haze can be determinedusing, for example, the method of ASTM-D 1003-95.

Also disclosed are methods for preparing articles. These methods includeproviding a substrate with a first polyester surface and a secondpolyester surface, coating a curable primer composition onto at leastone of the first polyester surface or the second polyester surface ofthe substrate, drying the curable primer composition, heating whilestretching the substrate and the curable primer composition to form acrosslinked primer layer on the stretched polyester surface, andapplying an optically clear heat activated adhesive onto the crosslinkedprimer layer to form an optically clear heat activated adhesive layer.Because the curable primer composition is coated on the substrate priorto heating while stretching (a process referred to as “tentering”), thecurable primer coating is sometimes referred to as a “pretentercoating”. This curable pretenter primer coating comprises apolyurethane-based dispersion and a crosslinker, such as are describedin detail above.

In some embodiments, the primer composition is coated onto both thefirst and second polyester surfaces of the substrate to form first andsecond cured primer layers. Coating both surfaces not only provides anarticle with both surfaces that are suitable for receiving additionalcoatings, but also provides an article in which both sides are the same.Having film articles where both sides are the same eliminates the needto take care in processing to remember which side has the primercoating. Additionally, the primer coatings of this disclosure, besidesproviding a modified surface suitable for receiving additional coatings,have been found to provide increased film handling ability. Thisincreased film handling ability includes, for example, enhanced slippingover rollers and easier winding and unwinding of film rolls. Thisenhanced slippage can be attained or enhanced in some embodiments byincluding various polymeric or inorganic additives in the primercompositions. These additives include, for example, slip additives suchas the water-based dispersion of fumed silica commercially availablefrom Degussa Corporation (Parsippany, N.J.) as “AERODISP W 1226”.

The curable primer coating may be coated onto one or both of thepolyester surfaces of the substrate using any suitable coating orapplying method or combination of methods useful for coating waterborneor solventborne mixtures. Examples of suitable coating equipment includeknife coaters, roll coaters, reverse roll coaters, notched bar coaters,curtain coaters, roto-gravure coaters, rotary printers and the like. Theviscosity of the aqueous or solvent mixture can be adjusted to the typeof coater used. After the coatings are applied, they may be dried by anysuitable drying process. Examples of suitable drying processes includeair drying and the application of heat to dry such as with an IR lamp oroven such as a forced air oven.

After the primer layer or primer layers are dried on the substrate, thecoated substrate can then be tentered or stretched in one or twodimensions in order to orient the film. The process of orienting film,particularly polyester films, is described in Volume 12 of TheEncyclopedia of Polymer Science and Engineering, 2nd edition, pages 193to 216. A typical process for fabricating biaxially oriented polyesterfilms comprises four main steps: (1) melt extrusion of the polyesterresin and quenching it to form a web, (2) drawing the web in thelongitudinal or machine direction, (3) subsequently or simultaneouslydrawing the web in the transverse direction to create a film, and (4)heat setting the film. If biaxial orientation is desired, the primercomposition may be coated on the multi-layer optical film after it hasbeen drawn in the machine direction but before it has been subsequentlydrawn in the transverse direction. Further discussion on the orientationof polymeric films can be found, for example in the PCT Publication WO2006/130142. Multi-layer optical films are typically produced inprocesses utilizing draw ratios in the range of 6:1 or greater,significantly higher than the 3.5:1-4:1 typically used in preparation ofmonolithic PET film. Unlike many primers used in the art, the primers ofthis disclosure have been found to yield coatings with excellentclarity, cosmetics, and adhesion properties even after draw at 6:1.

After the primed film article has been stretched and oriented, a varietyof different layers can be contacted to the primer surface. Among theselayers are optically clear heat activated adhesive layers, hardcoatlayers, optical layers, and pressure sensitive adhesive layers. All ofthese layers have been described in detail above and can be appliedusing conventional coating or laminating techniques.

EXAMPLES

Advantages and embodiments of this disclosure are further illustrated bythe following examples, but the particular materials and amounts thereofrecited in these examples, as well as other conditions and details,should not be construed to unduly limit this disclosure. In theseexamples, all percentages, proportions and ratios are by weight unlessotherwise indicated.

These abbreviations are used in the following examples: g=gram;min=minute; mol=mole; hr=hour; mL=milliliter; nm=nanometers; wt=weight;fpm=feet per minute; psi=pounds per square inch; kPa=kilo Pascals;PSA=pressure sensitive adhesive. If not otherwise indicated chemicalsare available from Sigma-Aldrich, St. Louis, Mo.

Table of Materials Material Designation Description PVB Polyvinylbutyraltype AR-11 PVB (0.015″) commercially available from Solutia (St. Louis,MO). HAA-1 Optically clear heat activated adhesive, 35 mil (890micrometers) thick, commercially available from DuPont Chemicals,Wilmington, DE, as “SentryGlasPlus”. HAA-2 Optically clear heatactivated adhesive, 15 mil (380 micrometers) thick commerciallyavailable from Bridgestone Corp, Tokyo, JP, as “EVASAFE”. AIC-1Aliphatic isocyanate crosslinker commercially available from BayerMaterial Science LLC (Pittsburgh, PA) as BAYHYDUR 303 AIC-2 Aliphaticisocyanate crosslinker commercially available from Bayer MaterialScience LLC (Pittsburgh, PA) as BAYHYDUR 305 AIC-3 Aliphatic isocyanatecrosslinker commercially available from Bayer Material Science LLC(Pittsburgh, PA) as BAYHYDUR 401-70 AIC-4 Aliphatic isocyanatecrosslinker commercially available from Bayer Material Science LLC(Pittsburgh, PA) as BAYHYDUR XP2487/1 AIC-5 Aliphatic isocyanatecrosslinker commercially available from Bayer Material Science LLC(Pittsburgh, PA) as BAYHYDUR XP7165 AIC-6 A self emulsifiable aliphaticpolyisocyanate crosslinker commercially available from Perstorp Polyols,Inc. (Toledo, OH) as ESAQUA XD 401. AIC-7 A water dispersible aliphaticpolyisocyanate crosslinker commercially available from Perstorp Polyols,Inc. (Toledo, OH) as ESAQUA XM 501. ARC-1 An amino-resin crosslinkercommercially available from Cytec Industries Inc. (Woodland Park, NJ) asCYMEL 327. BI-1 Blocked isocyanate commercially available from BayerMaterial Science LLC (Pittsburgh, PA) as BAYHYDUR VPLS 2310 BI-2 Blockedisocyanate commercially available from Bayer Material Science LLC(Pittsburgh, PA) as BAYHYDUR BL 5335. BI-3 Blocked isocyanatecommercially available from Baxenden Chemicals Limited (Lancashire,England) as TRIXENE Bl 7986 BI-4 Blocked isocyanate commerciallyavailable from Baxenden Chemicals Limited (Lancashire, England) asTRIXENE Bl 7987. PUD-1 A solvent free 31% aqueous aliphatic polyesterpolyurethane dispersion commercially available from Alberdingk Boley,Inc. (Greensboro, NC) as U 9380. PUD-2 A solvent free 35% aliphaticpolyester-polycarbonate polyurethane dispersion commercially availablefrom Alberdingk Boley, Inc. (Greensboro, NC) as U 9150. PUD-3 Asolvent-free 25% aqueous aliphatic polyurethane dispersion prepared asdescribed below under “Synthesis of Polyurethane Dispersion 3”. Polyol-1Polyol commercially available from Bayer Material Science LLC(Pittsburgh, PA) as ARCOL POLYOL PPG 2000. Polyol-2 Polyol commerciallyavailable from Bayer Material Science LLC (Pittsburgh, PA) as ARCOLPOLYOL PPG 1025. H12MDI The diisocyanate, bis(4-isocyanatocyclohexyl)methane commercially available from Bayer Material Science LLC(Pittsburgh, PA) as an 80% solids solution in 2-butanone solvent. PU-1 Ahydroxyl functional polyurethane commercially available from BayerMaterial Science LLC (Pittsburgh, PA) as BAYHYROL B 130. Surfactant Aproprietary surfactant/wetting agent commercially available fromInternational Specialty Products (Wayne, NJ) as EASY WET 20. Slip AgentA 26% solids water-based dispersion of fumed silica commerciallyavailable from Degussa Corporation (Parsippany, NJ) as AERODISP W 1226.AEAPTMS 3-(2-aminoethylamino)propyltrimethoxy silane was used asreceived from Alfa Aesar, Ward Hill, MA. PAA Poly(allylamine)hydrochloride was used as received from Alfa Aesar, Ward Hill, MA.Coating Solution A A 25% solids solution in toluene of an acidcontaining PSA A, with the monomers 2-EHA:BA:AA in the ratio 48:47:5.Coating Solution B A 20% solids solution in toluene of an acid free PSAB, with the monomers IOA:AM in the ratio 94:6. 2-EHA 2-ethylhexylacrylate BA Butyl acrylate AA Acrylic acid IOA Isooctyl acrylate AMAcrylamide

Synthesis of Polyurethane Dispersion 3

Based on a pound/100 pound charge, an isocyanate terminated prepolymerwas prepared as follows. A mixture of Polyol-1 (0.003 eq), Polyol-1(0.020 eq), and dimethylolpropionic acid (0.024 eq, obtained from GEOSpecialty Chemicals) in 2-butanone (70% solids) with dibutyltindilaurate catalyst (0.1 wt %, obtained from Air Products Chemicals Inc),was gradually treated with an 80% solution of H12MDI (0.069 eq). Themixture was stirred at 102° C. (215° F.) for 3-4 hr. The formedprepolymer solution was cooled to 79° C. (175° F.) and then graduallyadded to a dilute aqueous solution of triethyl amine (0.009 eq, obtainedfrom Air Products and Chemicals Inc.) and ethylene diamine (0.017 eq,obtained from Dow Chemical Company). The mixture was stirred for 1 hrwith high agitation, and then stripped under reduced pressure to yield a25% solids aqueous polyurethane dispersion.

General Procedure for Coating Solution Preparation

Unless otherwise noted, all laboratory scale coating solutions were madein 100 g quantities. A vessel containing the primary polyurethane binderwas stirred, followed by gradual addition of the specific neatcrosslinker solution. Pre-mixed solutions of the crosslinkers were madeat 20% solids for larger scale experiments using more than about agallon of coating solution. The amount of isocyanate crosslinker solidsused in each case was 20% by wt of the total binder solids, i.e. a 4:1mixture of polyurethane to crosslinker. After stirring the binder andcrosslinker 15 min, deionized water was used to dilute the material to afinal concentration of 15% solids, and then Surfactant (0.08% of totalsolution wt) and Slip Agent (if used) were successively added. Thesolutions were stirred for another 15 min prior to use for coatingoperations. Alternate orders of addition, such as charging the binderand crosslinker to a stirred solution of deionized water and surfactantwere determined to perform equivalently.

Coating and Tentering Procedures

Laboratory film samples were coated using a #6 Mayer coating rodpurchased from RD Specialties, Inc. (Webster, N.Y.). The coated film wasdried in a 165° F. (74° C.) oven for 3-5 min, and then the opposite sideof the film was coated and dried similarly. The film was subsequentlystretched in a “KARO IV LABORATORY STRETCHING MACHINE” commerciallyavailable from Brückner, Siegsdorf, Germany using the followingprocedure: (i) Pre-heat for 25 s at 97° C. (ii) Simultaneously stretchin the machine direction (MD) 3.33 times and in the cross-web (TD)direction 3.46 times at 14%/s (iii) Heat the film for 60 s at 193° C.(iv) Stretch the film to 3.43 times in the MD and 3.56 times in the TDat 50%/s. For trials on manufacturing scale equipment, the coatings wereapplied using a reverse gravure roll coating process. The gravure rollspeed was set at 125% draw and a finish speed of 45.75 fpm. The doctorblade pressure was set at 40 psi. After coating, the films wereprocessed sequentially through a drying oven (130° F.), pre-heat andstretch zones (200-202° F.), heat set zone (422° F.), and lastly acooling zone (100° F.). The stretching parameters were nominally thesame as those described for the laboratory samples. The thickness of thedried coating was nominally 80-150 nm.

Multi-Layer Optical Film with PET Skins

Cast multi-layer optical film (MOF) was coated and then stretched beforeuse in the articles and laminates described here. After the stretchingand heat-set steps, the film is analogous to CM 875, a 2 mil (51micrometer) nominal quarter wave IR reflecting film comprising 224alternating layers of polyethylene terephthalte (PET) and coPMMA (polymethylmethacrylate), along with skin layers of the same PET on theexterior of the multi-layer stack. The film is described in U.S. Pat.No. 6,797,396 (Example 5).

Preparation and Testing of Glass Laminates

Glass laminates were 12 in×12 in. The construction of the laminates wasas follows: 2.1 mm glass/15 mil PVB/Experimental Film/15 mil PVB/2.1 mmglass. The laminates were run through a nip roller to push out residualair, and then run through an autoclave that was ramped to 285° F./175psi over 30 min, held for 30 min, and gradually cooled down over 30-60min.

Compressive shear testing was done using 1.00 in+/−0.02 in squaresamples that were cut from the 12″×12″ glass laminates prepared asabove. The square samples were loaded into a test fixture of a MTSAlliance RT/50 machine equipped with a 11,000 lb-f (50,000 N) load cellto apply a 45 degree compressive shear force. The load cell was moved ata rate of 0.1″/min. The force at which the glass laminate failed wasrecorded and the average value is reported as determined from 6-10repeat measurements.

Haze and percent transmission measurements were made using a BYK GardnerPlus AT-4725 instrument. Data is tabulated for both film samples andglass laminates.

Comparative Example C1

A film was made as described under “Multi-layer Optical Film with PETskins”. The film was not coated with primer, but was tentered asdescribed above in “Coating and Tentering Procedures” and made into aGlass/PVB/Film/PVB/Glass construction and tested as described under“Preparation and Testing of Glass Laminates”. The results are presentedin Table 1.

Comparative Example C2

A PAA coating solution was prepared as in U.S. Pat. No. 5,411,845,coated onto CM875 film as described above, tentered as described above,and made into a Glass/PVB/Film/PVB/Glass construction and tested asdescribed under “Preparation and Testing of Glass Laminates”. Theresults are presented in Table 1.

Comparative Example C3

A 1% AEAPTMS coating solution was prepared as in U.S. Pat. No.5,064,722. A Glass/PVB/Film/PVB/Glass construction was made identicallyto Comparative Example C1, but the film was first coated on both sidesof the multi-layer optical film with AEAPTMS as described under“Preparation and Testing of Glass Laminates”. The results are presentedin Table 1.

Comparative Example C4

A Glass/PVB/PVB/Glass construction was made and tested as in ComparativeExample C1 but without the multi-layer optical film with PET skins. Theresults are presented in Table 1.

Example 1

A coating solution was prepared as described under “General Procedurefor Solution Preparation” using PUD-1 as the primary binder and AIC-2 asthe crosslinker. A film was made and processed as described under“Multi-layer Optical Film with PET skins” and “Coating and TenteringProcedures”. The resultant processed film was made into aGlass/PVB/Film/PVB/Glass construction and tested as described under“Preparation and Testing of Glass Laminates”. The results are presentedin Table 1.

Example 2

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except that Slip Agent was added so that the levelof slip particles was 2.5% by weight of the dried coating. The resultsare presented in Table 1.

Example 3

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PUD-3 was used as the primary binder. Theresults are presented in Table 1.

Example 4

A coating solution, film, and laminate were made and tested as describedabove for Example 3, except that Slip Agent was added so that the levelof slip particles was 2.5% by weight of the dried coating. The resultsare presented in Table 1.

Example 5

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PUD-2 was used as the primary binder. Theresults are presented in Table 1.

Example 6

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PU-1 and ARC-1 were used as the primarybinder and crosslinker, respectively. The results are presented in Table1.

Example 7

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PU-1 and AIC-2 were used as the primarybinder and crosslinker, respectively. The results are presented in Table1.

Example 8

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PUD-3 and ARC-1 were used as the primarybinder and crosslinker, respectively. The results are presented in Table1.

Example 9

A coating solution, film, and laminate were made and tested as describedabove for Example 1, except PUD-3 and AIC-2 were used as the primarybinder and crosslinker, respectively. The results are presented in Table1.

TABLE 1 Compressive Optics (film) Optics (laminate) Shear % % % %Example Strength (N/in²) Haze Transmission Haze Transmission C1 2,777 NM* NM 0.7 85 C2 5,988 15 88 1.9 83 C3 3,881 17 89 1.1 86 C4 7,375 NMNM NM NM EX1 8750 3.0 92 0.9 88 EX2 7485 3.9 95 0.7 89 EX3 7820 3.0 921.0 86 EX4 8994 4.2 96 0.7 89 EX5 8,087 3.28 NM 0.44 NM EX6 5,259 3.12NM 0.49 NM EX7 3,791 1.29 NM 0.54 NM EX8 7,787 1.15 NM 0.47 NM EX9 7,9360.62 NM 0.46 NM *NM = not measured

Examples 10-16

Coating solutions, coated and processed film, and laminate constructionswere made and tested as described above for Example 1 using PUD-1 as theprimary binder and a variety of different crosslinkers. For Example 10the crosslinker was AIC-6; for Example 11 the crosslinker was AIC-7; forExample 12 the crosslinker was AIC-1; for Example 13 the crosslinker wasAIC-2; for Example 14 the crosslinker was AIC-3; for Example 15 thecrosslinker was AIC-4; for Example 16 the crosslinker was AIC-5. Theresults are presented in Table 2.

TABLE 2 Optics (film) Optics (laminate) Compressive Shear % % % %Example Strength (N/in²) Haze Transmission Haze Transmission EX10 7,1272.1 90.5 0.8 86.8 EX11 7,572 6.4 91.0 1.0 87.0 EX12 7,519 1.5 92.5 0.787.5 EX13 6,828 3.0 92.0 1.0 86.0 EX14 7,914 2.1 90.5 0.8 86.8 EX156,184 8.0 91.0 1.6 87.5 EX16 7,285 2.1 91.5 0.8 86.0

Examples 17-23

Coating solutions, coated and processed film, and laminate constructionswere made and tested as described above for Example 1 using PUD-3 as theprimary binder and a variety of different crosslinkers. For Example 17the crosslinker was AIC-6; for Example 18 the crosslinker was AIC-7; forExample 19 the crosslinker was AIC-1; for Example 20 the crosslinker wasAIC-2; for Example 21 the crosslinker was AIC-3; for Example 22 thecrosslinker was AIC-4; for Example 23 the crosslinker was AIC-5. Theresults are presented in Table 3.

TABLE 3 Optics (film) Optics (laminate) Compressive Shear % % % %Example Strength (N/in²) Haze Transmission Haze Transmission EX17 7,1090.9 80.0 0.7 85.0 EX18 7,797 0.9 80.0 0.7 85.0 EX19 2,509 2.1 92.0 0.788.0 EX20 7,649 3.0 92.0 1.0 86.0 EX21 4,875 3.0 93.0 0.9 87.0 EX226,911 1.5 92.5 0.7 87.5 EX23 8,665 2.1 90.5 0.8 86.8

Examples 24-27

Coating solutions, coated and processed film, and laminate constructionswere made and tested as described above for Example 1 using PUD-1 as theprimary binder and a variety of different crosslinkers. For Example 24the crosslinker was BI-1; for Example 25 the crosslinker was BI-2; forExample 26 the crosslinker was BI-3; for Example 27 the crosslinker wasBI-4. The results are presented in Table 4.

Example 28-30

Coating solutions, coated and processed film, and laminate constructionswere made and tested as described above for Example 1 using PUD-3 as theprimary binder and a variety of different crosslinkers. For Example 28the crosslinker was BI-2; for Example 29 the crosslinker was BI-3; forExample 30 the crosslinker was BI-4. The results are presented in Table4.

TABLE 4 Optics (film) Optics (laminate) Compressive Shear % % % %Example Strength (N/in²) Haze Transmission Haze Transmission EX24 7,1572.5 90 0.9 84 EX25 8,359 1.8 90 0.9 85 EX26 8,201 2.5 89 1.0 78 EX277,749 2.9 90 0.8 78 EX28 8,445 2.5 92 1.0 87 EX29 8,932 3.2 93 1.0 87EX30 8,744 4.2 92 1.0 86

Examples 31-33 and Comparative Examples C5 and C6

Glass laminates were made using optically clear heat activated adhesivesin conjunction with two side polyurethane-base primed film andnon-primed bare film. The film, both with and without primer, was madeas described under “Multi-layer Optical Film with PET skins”. The twoprimed films were as described in Examples 2 and 4. The non-primed filmwas as described in Comparative Example 1. The glass laminates were madewith two optically clear heat activated adhesives HAA-1 and HAA-2. Thefinished laminate constructions were 2.1 mm glass/optically clear heatactivated adhesive/film/optically clear heat activated adhesive/2.1 mmglass.

The glass laminates were made by the following method. Laminates werefirst de-aired in a vacuum bag. The vacuum bagged laminates were thenplaced in an autoclave and ramped to 135° C. (275° F.)/1207 kPa (175psi) and held for 60 min after which they were gradually cooled downbefore removal from the autoclave. Examples 31 and 32 were done usingthe films of Example 1 and 2 respectively but with HAA-1 replacing PVB.Example 33 was done with the film of Example 2 but with HAA-2 replacingPVB. Comparative Examples C5 and C6 were done with the film ofComparative Example C1 but with HAA-1 and HAA-2 respectively replacingPVB. Testing was carried out as described in “Preparation and Testing ofGlass Laminates”. The results are presented in Table 5.

TABLE 5 Optics (laminate) Compressive Shear % % Example Strength (N/in²)Haze Transmission C5 13835 0.62 88 C6 15843 0.69 88 EX31 23128 0.62 88EX32 22995 0.68 88 EX33 16453 0.78 88

Examples 34-41 and Comparative Examples C7-C10

Solvent based acrylic polymer PSA adhesive coating solutions were notchbar coated directly on to primed PET substrates and convection ovendried at a dry coating thickness of 6.35 micrometers (0.25 mil+/−0.1mil). Two coating solutions were used, Coating Solution A and CoatingSolution B. The primed substrates were Primed Substrate C which was thesubstrate as described in Example 1, Primed Substrate D which wassubstrate as described in Example 2, and Primed Substrate E which wassulfopolyester primed PET (as described in U.S. Pat. No. 5,439,785). ThePSA coated primed PET substrates were applied to prewashed/precleanedborosilicate glass by both dry and wet application techniques. Sampleswere peeled from the glass at an approximate 90° angle immediately afterapplication as well as after heat aging in a convection oven at 66° C.(150° F.) for 24 hr, 72 hr, and 1 week. Peel rates were in excess of 90in/min (229 cm/min). Following peel testing, the amount of adhesivetransfer to the glass substrate was evaluated. The results are presentedin Table 6.

TABLE 6 24 hr Immediate peel: 72 hr 1 week peel: PSA PSA peel: PSA peel:PSA Primed Application transfer to transfer to transfer to transfer toExample substrate/PSA method glass glass glass glass EX34 Substrate DryNone None None None C/PSA A EX 35 Substrate Dry None None None NoneC/PSA B EX 36 Substrate Dry None None None None D/PSA A EX 37 SubstrateDry None None None None D/PSA B C7 Substrate Dry ~25% ~5-10% ~5-10%~5-10% E/PSA A C8 Substrate Dry ~5-10% 25-50% 25-50% 25-50% E/PSA B EX38 Substrate Wet 25-50% None None None C/PSA A EX 39 Substrate Wet25-50% None None None C/PSA B EX 40 Substrate Wet 25-50% None None NoneD/PSA A EX 41 Substrate Wet 25-50% None None None D/PSA B C9 SubstrateWet 25-50% ~5-10% ~5-10% ~5-10% E/PSA A C10 Substrate Wet 25-50% 25-50%25-50% 25-50% E/PSA B

What is claimed is:
 1. An article comprising: a substrate with a firstpolyester surface and a second polyester surface; a crosslinkedpolyurethane-based primer coated on the first polyester surface; and anoptically clear heat activated adhesive adjacent to the crosslinkedpolyurethane-based primer.
 2. The article of claim 1, wherein thecrosslinked polyurethane-based primer comprises the reaction product ofa polyurethane-based dispersion and a crosslinker.
 3. The article ofclaim 1, wherein the crosslinked polyurethane-based primer comprises apolyurethane-based, a polyester-based polyurethane, apolycarbonate-based polyurethane primer, or a combination thereof. 4.The article of claim 1, wherein the crosslinked polyurethane-basedprimer comprises an aliphatic polyurethane-based or aliphaticpolyester-based polyurethane primer.
 5. The article of claim 2, whereinthe crosslinker comprises an aliphatic diisocyanate, a blockedisocyanate, melamine formaldehyde crosslinker, or a combination thereof.6. The article of claim 1, wherein the substrate comprises a multi-layersubstrate.
 7. The article of claim 1, wherein the substrate comprises anoriented film.
 8. The article of claim 1, wherein the optically clearheat activated adhesive comprises a polyacrylate hot melt adhesive, apolyvinyl butyral, an ethylene vinyl acetate, an ionomer, a polyolefin,or a combination thereof.
 9. The article of claim 1, further comprisinga crosslinked polyurethane-based primer coated on the second polyestersurface.
 10. The article of claim 1, further comprising a layer adjacentto the crosslinked polyurethane-based primer on the second polyestersurface, the layer comprising an optically clear heat activated adhesivelayer, a cured acrylate layer or a pressure sensitive adhesive layer.11. An article comprising: a substrate with a first polyester surfaceand a second polyester surface; a crosslinked polyurethane-based primercoated on the first and second polyester surfaces; and a pressuresensitive adhesive layer adjacent to the crosslinked polyurethane-basedprimer on the first polyester surface.
 12. A laminate constructioncomprising: a first glazing substrate comprising a first major surfaceand a second major surface; a film article adhered to the first majorsurface of the first glazing substrate, the film article comprising asubstrate with a first polyester surface and a second polyester surface;a first crosslinked polyurethane-based primer coated on the firstpolyester surface, and a second crosslinked polyurethane-based primercoated on the second polyester surface; and a first optically clear heatactivated adhesive adjacent to the first crosslinked polyurethane-basedprimer and a layer adjacent to the second crosslinked polyurethane-basedprimer.
 13. The laminate construction of claim 12, wherein the layeradjacent to the second crosslinked polyurethane-based primer comprises asecond optically clear heat activated adhesive, and further comprising asecond glazing substrate comprising a first major surface and a secondmajor surface with the first major surface of the second glazingsubstrate being adhered to the second optically clear heat activatedadhesive, such that the film article comprises an interlayer article andthe first glazing substrate, interlayer article and second glazingsubstrate form a sandwich construction.
 14. A method of preparing anarticle comprising: providing a substrate with a first polyester surfaceand a second polyester surface; applying a curable primer compositiononto at least one of the first polyester surface or the second polyestersurface of the substrate, wherein the curable primer compositioncomprises a polyurethane-based dispersion and a crosslinker; drying thecurable primer composition; heating while stretching the substrate andthe curable primer composition to form a crosslinked primer layer on thestretched polyester surface; and applying an optically clear heatactivated adhesive onto the crosslinked primer layer to form anoptically clear heat activated adhesive layer.
 15. The method of claim14, wherein curable primer composition is coated onto the first andsecond polyester surfaces of the substrate to form first and secondcured primer layers.
 16. The method of claim 14, wherein heating whilestretched comprises stretching in at least one direction.
 17. The methodof claim 16, wherein stretching comprises biaxial stretching.
 18. Themethod of claim 15, further comprising applying of a second opticallyclear heat activated adhesive onto the second cured primer layer to forma second optically clear heat activated adhesive layer.
 19. The methodof claim 15, further comprising applying a curable material onto thesecond cured primer layer and curing to form a cured layer adjacent tothe second cured primer layer.
 20. The method of claim 19, wherein thecured layer comprises a hardcoat and/or an optical layer.
 21. The methodof claim 15, further comprising applying a pressure sensitive adhesivematerial onto the second cured primer layer to form a pressure sensitiveadhesive layer adjacent to the second cured primer layer.